When customers used the site to ascertain delivery costs they were led to two Excel spreadsheets, one containing order details and the other containing all customer details and contacts.
"This was resolved late yesterday [Wednesday]," said a company representative. "It was a mistake that we will try hard to stop happening in the future. We can only apologise to all those customers involved."
Although credit card details were not displayed on the spreadsheets, 449 customers' bank phone numbers were. Gateway did not know exactly how many people accessed the site on Thursday, nor could the company specify how or why security had been breached.
This represents yet another example of poor security by major IT firms, such as Microsoft which failed to protect its Web sites from hackers last week.